'Jets' from Enceladus Geysers May Be Huge Curtain-Like Sheets of Ice and Vapor

Data going back as far as 2005 has told us that Saturn's moon Enceladus is covered with active hot geysers that emit "jets" of water vapor, which made it one of the top candidates for discovering microbial alien life. But now, new research indicates that the "jets" may not be jets at all, but giant sheets of vapor and ice that created the illusion of discrete emissions.

Back in 2005, NASA's Cassini detected plumes of water vapor and icy particles ejecting from Saturn's ice-covered moon. Cassini's cameras were ultimately able to map 101 geysers on the surface of Enceladus that erupted from "tiger stripe" fractures: distinctive geological features of Enceladus that are characterized by sub-parallel linear depressions.

At first, scientists assumed from the photographs that the geysers erupted in "jets" of water vapor and ice. But upon closer examination of the Cassini images, researchers began to discern that this hypothesis is not consistent with the data. "What became evident very quickly was that a lot of the tiny little jets we looked at were real slippery - we couldn't triangulate them," Joseph Spitale of the Planetary Science Institute told Space. "We also saw really broad areas of emissions that couldn't be jets - they were just huge fuzz."

Ultimately, they concluded that many of these "jets" were not separate from each other, but rather collectively formed giant walls. "A lot of things that looked like jets were optical illusions - they were really curtains," said Spitale.

Spitale and his team theorize that the curtains were mistaken for jets because the tiger stripe fractures tend to "meander," or fail to form in a straight line, causing the curtains to fold against each other. Where multiple curtains are coming into contact, there's a greater concentration of vapor and ice particles, which resembled jets in the Cassini images.

"This should have been obvious, but it was a big surprise to us," Spitale said, adding that in five Cassini images between 2009 and 2010, "it looks like most of the time, most of the fractures are turned on," Spitale said. "They're emitting at some level all the time."

Spitale clarifies, however, that there may very well still be jets of water vapor on Enceladus, just not as many as we thought. He speculates that there may be jets where multiple fractures come into contact with each other, or in areas where falling debris has opened a wider crack in the surface.